Drones—An Open Access Journal

Since the beginning of aviation, unmanned aerial systems have been a challenge for scientists and engineers. The first automatic airplane developed by the Wright brothers in 1916 and the drone used by the British Royal Navy for gunnery practice in 1933 serve as examples. The possibility of controlling an aircraft without a pilot has been a challenge, both from the civil and military point of view. Nowadays, the proliferation of unmanned aerial systems, popularly known as “drones”, is a reality for local policy makers, regulatory bodies, mapping authorities, start-ups and consolidated companies. The number of developed drones has increased threefold from 2005 to present and, additionally, a relevant increase has been observed in the civil/commercial type of platforms, especially in 2012 and 2013 [1]. There are many uses and benefits of drones based on their own pilot system (autonomous or remotely controlled) and sensory to achieve accurate positioning and to acquire a great variety of data. By this binomial, drones are an efficient solution for the observation, inspection, measurement and monitoring of territory; ensuring better spatial, radiometric, spectral and temporal resolutions than any manned aerial vehicle and satellite. Drones have caused an unprecedented impact on society and the economy. According to recent market research [2], the global drones market revenue is worth $6,800 M United States Dollars (USD) as of 2016 and is expected to grow up to $36,900 M USD by 2022. The low-cost of the sensors integrated in aerial platforms of different designs has launched its application and proliferation more than its military origin, offering new applications and leading to more clients in the civil sector. It is in this last sector where more progress by drones is expected. For instance, new developments in robotics, computer vision and geomatic technologies, together with more research and development supported by technological centres and universities, allow the improvement of technology transfer with an important insight into new markets. While it is true that these civil-drones are still far from the systems used in military applications, studies and advances in the development of technology can offer professional systems with new, improved and promising features. In this sense, it is expected that the main advances of drones may occur in the following lines: (1) the emergence of new sensors that allow the improvement of the geometric and radiometric resolution, as well as the spectral range; (2) the evolution of new platforms that improve robustness and increase autonomy; (3) the development of software, from the navigation and communication with the platform to the processing and analysis of the images captured; (4) new applications in emerging sectors: logistics, disaster assistance, security and surveillance, health and marine science, among others. The emergence of new sensors, thanks to advances in microelectronics and nanotechnology [3–5] will be crucial in the coming years. In fact, the evolution of integrated circuitry and radio-controlled systems in the late twentieth century was key in the advent of modern drones. At present, improvements in miniaturization and the development of new sensors (e.g., computer boards, Global Navigation Satellite System (GNSS) receivers and antennas, Inertial Measurement Systems (IMU), cameras, etc.) has entailed a very important evolution for drones [6–8]. These advances have appeared in the range of existing sensors both active (e.g., Light Detection and Ranging (LiDAR) and Synthetic aperture radar (SAR)) and passive (e.g., multispectral, hyperspectral and thermographic cameras).